Attention Deficit Hyperactivity Disorder

Attention Deficit Hyperactivity Disorder

Introduction

Attention-Deficit Hyperactivity Disorder (ADHD), once called hyperkinesis or minimal brain dysfunction, is one of the most common mental disorders among children. (Elia, Ambrosini, Rapoport, 1999) It affects 3 to 5 percent of all children, with approximately 60% to 80% of these children experiencing persistence of symptoms into adolescence and adulthood, causing a lifetime of frustrated dreams and emotional pain. There are two types of attention deficit hyperactivity disorder: an inattentive type and a combined type. The symptoms of ADHD can be classified into three categories: inattention, hyperactivity, and impulsivity. This behaviour stops ADHD sufferers from focusing

deliberately on organising and completing a specific task that they may not enjoy, learning new skills or information is proved to be impossible. An example of such behaviour is recognised by the report written by the National Institute of Mental Health where one of the subjects under study was unable to pass schooling examinations due to her inattentive behaviour. Such behaviour can damage the person's relationships with others in addition to disrupting their daily life, consuming energy, and diminishing self-esteem. (National Institute of Mental Health 1999) There are also secondary symptoms which are associated with ADHD, such as learning disorders, anxiety, depression and other mood disorders, tic disorders, and conduct disorders. (Spencer, Biederman, and Wilens 1999 in Monastra V, Monastra D, George, 2002)

Stimulant drugs are widely used to treat the symptoms of ADHD. These stimulants dramatically reduce the hyperactivity of sufferers and improve their ability to focus, learn and work. Such medication may also improve physical coordination, for instance handwriting and sports. Research completed by the National Institute of Mental Health (NIMH) suggests that these medicines may also help children with an accompanying conduct disorder to control their impulsive, destructive behaviours. The three medications that have been proven by the NIMH to be most effective in both children and adults suffering from ADHD are: methylphenidate (Ritalin), dextroamphetamine (Dexedrine or Dextrostat), and pemoline (Cylert). (NIMH 1999) Yet there is currently much research on the treatment of attention-deficit hyperactivity disorder, such as the three experiments discussed in this paper. Experiment 1 provides research on the effects of atomoxetine, which is a stimulant drug provided for the treatment of ADHD. Stimulants such as Concerta, Metadate CD, Ritalin LA, Adderall XR, and Focalin are discussed in the second experiment. On the other hand the third aspect of research on ADHD provides information not only on stimulants but also on EEG biofeedback and the effect of parental style of the child's symptoms.

Experiment 1

Research completed by the American Psychiatric Association was assessing the efficiency of atomoxetine, a stimulant drug used for the treatment of attention-deficit hyperactivity disorder. This experiment involved 171 children and adolescents suffering from ADHD randomly treated with either atomoxetine or placebo. Atomoxetine is a new investigational compound, which has been helpful for children and adults with ADHD when taken twice daily. Atomoxetine, such as other stimulant drugs, is a "potent inhibitor of the presynaptic norepinephrine transporter with minimal affinity for the other noradrenergic receptors or the other neurotransmitter transporters or receptors" (Michelson, et al, 2002). This neurotransmitter plays an important role in modulating the brain systems that control attention and activity. (Brown University, 2003) The aim of this research was to examine whether an effective drug taken twice daily could also be effective administered only once a day. When taken twice daily atomoxetine may result in side effects such as gastrointestinal incidents, like nausea or vomiting. In this case only two out of 171 children receiving atomoxetine terminated treatment due to adverse events. Other physical effects resulting from the treatment is increase in cardiovascular tone, which are pulse and the systolic blood pressure, and also a decrease in weight. The most important finding of the research is that the once daily dose in the morning was consistent throughout the day into the evening. This finding is strange because the approximate life of the atomoxetine plasma is only four hours long, therefore effects should not be prolonged over four hours. As a result of this research patients with attention deficit hyperactivity disorder can now be treated with a once daily dose, which is a lot more practical for children.

Experiment 2

Another trial that has been completed on the topic of treatment of attention deficit hyperactivity disorder has included five newest Food and Drug Administration (FDA) approved stimulant agents. These are: Concerta, Metadate CD, Ritalin LA, Adderall XR, Focalin. (Edwards, 2003) Older stimulant drugs, used for treatment of ADHD, are typically characterized by a short duration of behavioural effect requiring multiple daily doses; this can pose as an uncomfortable and embarrassing experience, especially for children during schooling.

"Innovative technology has fuelled the development of new release mechanisms and isolation of active enantiomer components with the hopes of enhancing the duration of action and improving the safety and effectiveness of stimulant agents." (Monastra V, Monastra D, George, 2002)

As a result of such research several new stimulant agents have been released as one of the treatment options. Concerta was the first extended relief or long lasting drug available for the sufferers of ADHD. Before Concerta was available, treatment was provided through continuous doses of stimulants throughout the day. This medicine was designed to provide two peak concentrations released from the capsule; one from the coating, releasing the initial 22% of the overall dose within the fist couple of hours, and then the rest 6 to 8 hours later. Metadate CD was the second stimulant drug on the market that was used for the treatment of ADHD. A recent trial between Metadate CD and Concerta, demonstrated that Metadate CD provides a significant improvement in morning and afternoon control of ADHD symptoms. Table 1 demonstrates the differences and similarities between Concerta and Metadate.

Table 1

Comparative characteristics of newly approved psychostimulants

Agent Concerta Metadate